Electbic railway system



(No Model.)

3 Sheets-Sheet 1. E. J. SPRAGUE.

I ELECTRIC RAILWAY SYSTEM.

Patented Aug. 4, 1885.

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(No Model.) 3 Sheets-Sheet 2. F. J. SPRAGUE.

ELBGTRIG RAILWAY SYSTEM. No. 323,459. w, Patented Aug. 4, 1885.

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F. J. SPRAGUE.

ELECTRIC RAILWAY SYSTEM.

No. 323,459. Patented Aug. 4, 1885,.

ATTES= INVENTUB:

UNITED` STATES v Pn'rnnfr trice.

FRANK J. SPRAGUE, OF NEW YORK, N. Y., ASSTGNOR TO THE SPRAGUE ELECTRICRAILVAY AND MOTOR COMPANY.

ELECTRIC-RAILWAY SYSTEM.

SPECIFICATION forming part of Letters Patent No. 323,459, dated August4, 1885.

Application filed January 19, 1885. (No model.)

To all whom it may concern.-

Y Be it known that I, FRANK J. SrRAeUn, of N ew York, in the county andState of New York, haveinvented a certain new and useful Improvement inElectric-Railway Systems, of which the' following is a specification.

The invention relates to those systems for electric railways in whichcontinuous main conductors are employed, and workingcondoctors, fromwhich the motors derive current, divided into sections, each sectionbeing connected with the continuous main conductors; and more especiallysaid invention relates to apparatus controlled by the position of themotors for making and breaking the connections between the mainconductors and .the workingconductors, whereby each secL tion is placedin circuit when the train approaches it, and remains in circuit whilethe train is upon it, whether the motor of the train is vusing a greateror less quantity of cu rrent, or none at all; and as soon as the trainhas left the section its circuit is broken, that of the next section inadvance having been previously closed. Further, by the use of myinvention, when the train is on one section the working-conductors ofthe next section may be crossed or joined together electrically atalmost any point without produc ing a short circuit, it being possibleto shortcircuit such conductors only at a very small portion of theirlength, while on other sections than those next adjacentit is impossibleto produce a short circuit at all.

ln carrying out my invention each working section has preferably twoconnections to the main conductors-*one permanent, the other through aswitch controlled partially by the current of said permanently-closedconductor and partly by its own current. The motors and workingconductors are so arranged relatively that the motor closes thepermanent connection of a section before it is fully on that section,and the switch is thus operated to close the otherorelectrically-controlled connection. At the same time one connection ofthe section which the motor is leaving is broken, but current passesthrough the other one and through one of the conductors of the 'advancedsection to propel the motor completely upon the latter, which breaks theremaining connection ofthe circuit just left.

An electro-magnetic device for controlling branch circuits must beindependent of the strength and continuity of the current, or ofthedirection of the current through the motor, because there are severaldifferent conditions which may arise when a motor is on a section. Suchconditions are as follows:

First. lf the motor is doing work, it taking current from the mainconductors, but not a uniform current, in which case the electromagneticdevices in circuit will be energized with a variable magnetic movement.

Second, lf the motor is being driven by the momentum of the train, as indescending a downgrade or slowing down, it becomes a generator and givesback current to the line, and so will reverse the current in theelectromagnetic switching devices.

Third. W'hen the motor is in the transitional sta-ge of j ust changingfrom doing work as a motor to doing work as a generator, itselectconiotive force is just sufficient to supply its own iield withouttaking from the line or giving to it. In this case there will be nocurrent in the electromagnetic switching devices.

Fourth. A motor may be at rest on a section without using any current atall.

It is evident that a motor on a section may pass through all theseconditions in rapid succession, or may remain in any one of them for aconsiderable time.

My invention is illustrated in the accompanying drawings, in whichFigure 1 is a general plan view and diagram of an electric railwaysystem embodying said -invention. Figs. 2, 3, and 4 are diagramsillustrating modified arrangements. Fig. 5 is an enlarged View inelevation of the preferred form of electromagnetic switching device;Fig. 6, a View of the same, with the magnets in section; and Fig. 7, aview of a modified form of the device.

A railway-line is shown in Fig. l, having two tracks, A A and B B, Eachtrack has two intermediate rails, a a' and?) b", which are theworking-conductors from which the motors O and C' derive current. Theworkingconductors may, however, be ol' any other suit IOC ` able formand placed in any convenientsi-tuation, so that the motors canreceivevcurrent from them; or, in some cases, the grounded rails of the trackform one side of each working-circuit. Only a portion of the motor C isshown, there not being sufficient space to show the whole of it intheposition in which it is placed. The connections and local circuits ofthe motors are not shown. They may be of any suitable character.

P N are continuous main conductors extending the whole length of ltheline. Both tracks are supplied from these main conductors by means ofbranch conductors c c c2, &c., and d d cl2, 850.

rlhe feature of supplying a double track from a single main circuit isnot claimed herein, being claimed in another application for LettersPatent.

D D represent the dynamo-'electric machines at the generating-stations,of which there are any suitable number, according to the length oftheline and the'power required. They are connected with the main conductorsby supply conductors p n.

The electro-'magnetic circuit-controlling'apparatus (shown in detail inFigs. 5 and 6) consists of electro-magnet or solenoid, E, havingI twosets of coils wound in the same direction, one set being included in thebranch conductor c, (or c c2, &c.,)the other in branch conductor, d, (ord d2, &c.) Conductorsc are continuous permanent connections between amain conductor and the working-conductor of the same polarity. Eachconductor is broken and closed at a switch, which preferably consists oftwo upright stationary contact-plates, e e', which are bridged to closecircuit by thecontactsplate e2,` which makes-a rubbing-con` tact withboth of them. The rod f, which supports plate e2, is carried by themovable core g of the solenoid or hollow electro-magnet E, which, whenenergized, drawsl its core downward. Another magnet or solenoid, i, isalso included in both conductors; but on this magnet the two sets ofcoils are wound differentially and equally, so that when both are incircuit the magnet is inactive. magnet z' carries a catch, Z, and therod fhas upon it a projection, n, with which said catch engages, andfrom which it is withdrawn when the magnet is energized.

The working-conductor-sections 1, 2, and 3 are formed by interposedshort'sections of insulation, m m. The ends of theV sections preferablyoverlap, as shown, so'that the motor leaves one working-conductor of asection beforethe other.

The operation of these devicesis as follows: The arrows by the sides ofthe tracks indicate the directionot' movement of motors thereon. Whenthe motor C crosses the insulating-section m of conductor a, which liesnext in its path-that is, when it reaches the position mv 'relative tothe working-conductors-a circuit is at once closed from main conductorI? by branch conductor c', working-conductor a,

tact.

The core 7c of through the motor to working-conductor a', and'by-.branch conductor cl2 of section 3 to `main conductor N. One coil ofmagnet E of section 2 is thus closed and its core is attracteddownwardly, closing circuit at e2; but as yet no current passes at thiscontact. At the same timebraneh conductor el of section 3 is cut out ofcircuit, the motor having left the working-conductor with which thisbranch conductor is connected, and the remaining coil or magnet i ofsection 3 draws back the core of said magnet and unlocks the switch ofthat section. The switch is still, however, kept closed by the currentin d'l so long as the motor is still in connection with the section; butas soon as the motor passes over the insulating-section m of conductor athe circuit of section 2 is closed through c and d and the motor, bothcoils on the locking-magneti of section 2 become equal, that magnetbecomes inactive, and the spring on its core throws the core and thecatch out and locks the switch. At the same time the circuit through dof section 3 is broken and the magnet E of that section becomesinert,and the spring q throws rod f and plate e2 up and breaks theswitch-con The motor having already broken the current in conductor d2,there is no sparking at the switch. Circuit to section 3 is thus broken,and that of section 2 is closed and remains positively locked until thetrain approaches the end of section 2, when the same operations arerepeated in the switching devices of sections l and 2 as have just beendescribed for sections 2 and 3. .The lower track is similarly equipped.On this trackis shown the motor'c on the overlappingportion of twoworking-sections, showing thearrangement of the switches and lockingdevices under these circumstances, which, however, has been al readydescribed with reference to motor G.

ItI will be seen that it is impossible to shortcircuit any sectionexcept at the part where the conductors overlap, and at this part it ispossible only when a motor isV on the next sec tion. Vhen a motor is ona section,circuit is constantly maintained to it. Variation in thecurrent upon the section, due to a change in load on the motor or to anyother cause, or an entire cessation of current through the motor, has noeffect on the switching devices.

In my application Serial No. 150,899 is set forth a method of brakingtrains by converting the motor into a generator giving current to theline. If a motor is in this condition when passing from one section toanother the switching devices operate just the same, their action notbeing dependent upon the direction of the current; or ifa train isreceiving no current, but running only on its own momentum, when itreaches the end of a section I can operate the switching devices fromthe motor by changing it into a generator in the manner set forth in theapplication last above referred to.

It is possible in some cases to dispense with the locking device and letthe switch be held closed by the motor-current. I prefer, how- ICO ever,to lock the switch positively while the motor is on the body of asection.

In the diagrannIiig. 2, the electro-magnetic switch of each section isplaced at the farther end of the section from that at which the motorapproaches it. The operation is substantially the saine. When the motorindicated at C is on the overlapping part at the beginning` of section2, circuit is closed through conductor c of section 2 and conductor diof section 3, and pivoted armature o of the magnet E of section 2 isattracted and closes conductor d. Section 2 is thus closed before themotor enters wholly upon it. At the same time conductor ci of section 3is first broken, the motor being, however, supplied with current throughc di until it is entirely on section 2, when d2 is broken and armature ois released.

The electro-magnetic switch in this and Figs. 3 and I is a simple form,with no locking device, shown merely for illustration.

In Fig. 3 each section has two switches, one at cach end. On the motorentering section 2, branch conductors c* and c5 are Iirst closed andboth magnets are energized, and afterward d" and d5 are closed,completing the circuit of the section when the motor is on the bodythereof.

In Fig. 4. the working-conductors do not overlap, but instead the motorhas diagonal connections-that is, one front and one rear contactso thatit leaves one conductor of a section before it leaves the other. This isevidently the equivalent of the overlapping conductors.

A differentmode of operating the locking device is shown in Fig. 7. Anadditional magnet, M, is employed, on which both conductors c d arewound,differentially, and this magnet has a third coil of tine wire, r,which is wound in series on the locking-magnet t'. W'hen the motor isfully on the section, magnet M is inert, its eoilsc d being equal anddifferential; but when the motor leaves one working-conductorof thesection, the sudden change of current in one of said coils c d inducesa. current in the line-wire coil rand energizes the magnet, so that thelatter attracts its core and unlocks the switch.

In Figs. 2, 3, and ft only one set of workingcendnctors is shown in eachfigure. I preer, however, to use two sets, as in Fig. 1.

Safetycatches n n are preferably placed in the branch conductors, sothat if a short circuit should accidentally occur on the overlappingport-ion of a section the system will be protected.

It is desired to keep the same potential at the terminals of all thegenerating-stations, and to this end I provide an indicating-eircuit, ss, in which an electrical indicator, t, is placed at each station,whereby the relative potentials are observed, and the generators can beregulated accordingly by means of the adjustable resistances o in theirfield-circuits. This feature is, however, not claimed herein, beingclaimed in another application.

What I claim isM l. In an electric-railway system, the combination ofthe main conductors, the workingconductors divided into sections, twobranch conductors for each section, and an electromagnetic switch for asection affected by the current in bot-h. said branch conductors,substantially as set forth.

2. In an electric-railway system, the combination of the mainconductors, the workingconductors divided into sections, apermanentconnection from one main conductor to a working-conductor of a section,and a connection from the other main conductor to the otherworking-conductor affected by the current of said permanent connection,substantially as set forth.

' 3. In an electric-railway system, the combination of the mainconductors, the workingconductors divided into sections, two branch.conductors-bue permanently, the other electro-magnetically, connected,and the electromagnetic controlling device included in the circuit ofboth said branch conductors, substantially as set forth.

4. In an electric-railway system, the combination ofthe main conductorsdivided into sections, two branch conductors, each connecting a main anda working conductor, a switch controlled bythe current in both saidbranch conductors, and a locking device for said switch controlled bythe current in both said branch conductorsl substantially as set forth.

5. In an electrierailway system, the co1nbination, with the mainconductors and the sectional workingconductors, and the motors soarranged relatively that a motoneontact inpassing from one section toanother leaves one of said working-comlnctors before it leaves theother, of the permanent connection between a main and a workingconductor of a section situated first in the path of the motor andincluding an electro magnetic switching device, and a connection fromthe main to the other working conductor of the section controlled by thesaid switching device, substantially as set forth.

6. The combination, in an electric railway, of continuous mainconductors, two sets of working-conductors supplied from said mainconductors, each of said sets being divided into sections, and devicescontrolled. by the movement of the trains or motors for controlling thecircuit of each section, substantially as set forth.

This specific-ation sig ned and witnessed this 12th day of December,185i.

FRANK. J. SPRAGUE. Vitnesses:

T. G. GREENE. .I r., E. C. RowLANn.

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